/*
 * Copyright (c) 2002 - 2006 IBM Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 */
package com.ibm.wala.cast.js.ipa.callgraph;

import com.ibm.wala.cast.ipa.callgraph.CAstCallGraphUtil;
import com.ibm.wala.cast.ipa.callgraph.StandardFunctionTargetSelector;
import com.ibm.wala.cast.ir.translator.AstTranslator;
import com.ibm.wala.cast.ir.translator.TranslatorToCAst;
import com.ibm.wala.cast.ir.translator.TranslatorToCAst.Error;
import com.ibm.wala.cast.js.loader.JavaScriptLoader;
import com.ibm.wala.cast.js.loader.JavaScriptLoaderFactory;
import com.ibm.wala.cast.js.translator.JSAstTranslator;
import com.ibm.wala.cast.js.translator.JavaScriptTranslatorFactory;
import com.ibm.wala.cast.js.types.JavaScriptMethods;
import com.ibm.wala.cast.js.types.JavaScriptTypes;
import com.ibm.wala.cast.loader.AstMethod.DebuggingInformation;
import com.ibm.wala.cast.tree.CAstEntity;
import com.ibm.wala.cast.tree.CAstNode;
import com.ibm.wala.cast.tree.impl.CAstImpl;
import com.ibm.wala.cast.tree.rewrite.CAstRewriterFactory;
import com.ibm.wala.cast.tree.visit.CAstVisitor;
import com.ibm.wala.cast.types.AstMethodReference;
import com.ibm.wala.cast.util.CAstPrinter;
import com.ibm.wala.cfg.AbstractCFG;
import com.ibm.wala.cfg.IBasicBlock;
import com.ibm.wala.classLoader.ClassLoaderFactory;
import com.ibm.wala.classLoader.IClass;
import com.ibm.wala.classLoader.Module;
import com.ibm.wala.classLoader.ModuleEntry;
import com.ibm.wala.classLoader.SourceModule;
import com.ibm.wala.classLoader.SourceURLModule;
import com.ibm.wala.ipa.callgraph.AnalysisScope;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.CallGraph;
import com.ibm.wala.ipa.callgraph.Entrypoint;
import com.ibm.wala.ipa.callgraph.impl.ClassHierarchyClassTargetSelector;
import com.ibm.wala.ipa.callgraph.impl.ClassHierarchyMethodTargetSelector;
import com.ibm.wala.ipa.cha.ClassHierarchyException;
import com.ibm.wala.ipa.cha.ClassHierarchyFactory;
import com.ibm.wala.ipa.cha.IClassHierarchy;
import com.ibm.wala.ssa.SSAInstruction;
import com.ibm.wala.ssa.SymbolTable;
import com.ibm.wala.types.MethodReference;
import com.ibm.wala.types.TypeName;
import com.ibm.wala.types.TypeReference;
import com.ibm.wala.util.collections.NonNullSingletonIterator;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.Reader;
import java.net.URL;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

public class JSCallGraphUtil extends com.ibm.wala.cast.ipa.callgraph.CAstCallGraphUtil {

  private static final boolean DEBUG = false;

  /**
   * the translator factory to be used for analysis TODO: pass the factory where needed instead of
   * using a global?
   */
  public static JavaScriptTranslatorFactory translatorFactory;

  /**
   * Set up the translator factory. This method should be called before invoking {@link
   * #makeLoaders()}.
   */
  public static void setTranslatorFactory(JavaScriptTranslatorFactory translatorFactory) {
    JSCallGraphUtil.translatorFactory = translatorFactory;
  }

  public static JavaScriptTranslatorFactory getTranslatorFactory() {
    return translatorFactory;
  }

  public static JSAnalysisOptions makeOptions(
      AnalysisScope scope, IClassHierarchy cha, Iterable<Entrypoint> roots) {
    final JSAnalysisOptions options = new JSAnalysisOptions(scope, /*
                                                                * AstIRFactory.
                                                                * makeDefaultFactory
                                                                * (keepIRs),
                                                                */ roots);

    options.setSelector(new ClassHierarchyMethodTargetSelector(cha));
    options.setSelector(new ClassHierarchyClassTargetSelector(cha));

    options.setSelector(new StandardFunctionTargetSelector(cha, options.getMethodTargetSelector()));

    options.setUseConstantSpecificKeys(true);

    options.setUseStacksForLexicalScoping(true);

    return options;
  }

  /**
   * @param preprocessor CAst rewriter to use for preprocessing JavaScript source files; may be null
   */
  public static JavaScriptLoaderFactory makeLoaders(CAstRewriterFactory<?, ?> preprocessor) {
    if (translatorFactory == null) {
      throw new IllegalStateException(
          "com.ibm.wala.cast.js.ipa.callgraph.Util.setTranslatorFactory() must be invoked before makeLoaders()");
    }
    return new JavaScriptLoaderFactory(translatorFactory, preprocessor);
  }

  public static JavaScriptLoaderFactory makeLoaders() {
    return makeLoaders(null);
  }

  public static IClassHierarchy makeHierarchyForScripts(String... scriptFiles)
      throws ClassHierarchyException {
    JavaScriptLoaderFactory loaders = makeLoaders();
    AnalysisScope scope = CAstCallGraphUtil.makeScope(scriptFiles, loaders, JavaScriptLoader.JS);
    return makeHierarchy(scope, loaders);
  }

  public static IClassHierarchy makeHierarchy(AnalysisScope scope, ClassLoaderFactory loaders)
      throws ClassHierarchyException {
    return ClassHierarchyFactory.make(scope, loaders, JavaScriptLoader.JS);
  }

  public static JavaScriptEntryPoints makeScriptRoots(IClassHierarchy cha) {
    return new JavaScriptEntryPoints(cha, cha.getLoader(JavaScriptTypes.jsLoader));
  }

  /**
   * Get all the nodes in CG with name funName. If funName is of the form {@code "ctor:nm"}, return
   * nodes corresponding to constructor function for {@code nm}. If funName is of the form {@code
   * "suffix:nm"}, return nodes corresponding to functions whose names end with {@code nm}.
   * Otherwise, return nodes for functions whose name matches funName exactly.
   */
  public static Collection<CGNode> getNodes(CallGraph CG, String funName) {
    boolean suffix = funName.startsWith("suffix:");

    if (suffix) {
      Set<CGNode> nodes = new HashSet<>();
      String tail = funName.substring(7);
      for (CGNode n : CG) {
        if (n.getMethod().getReference().getDeclaringClass().getName().toString().endsWith(tail)) {
          nodes.add(n);
        }
      }
      return nodes;
    }

    MethodReference MR = getMethodReference(funName);

    return CG.getNodes(MR);
  }

  public static MethodReference getMethodReference(String funName) {
    boolean ctor = funName.startsWith("ctor:");
    MethodReference MR;
    if (ctor) {
      TypeReference TR =
          TypeReference.findOrCreate(
              JavaScriptTypes.jsLoader, TypeName.string2TypeName('L' + funName.substring(5)));
      MR = JavaScriptMethods.makeCtorReference(TR);
    } else {
      TypeReference TR =
          TypeReference.findOrCreate(
              JavaScriptTypes.jsLoader, TypeName.string2TypeName('L' + funName));
      MR = AstMethodReference.fnReference(TR);
    }
    return MR;
  }

  /** @return The set of class names that where defined in the CHA as a result loading process. */
  public static Set<String> loadAdditionalFile(IClassHierarchy cha, JavaScriptLoader cl, URL url)
      throws IOException {
    return loadAdditionalFile(cha, cl, new SourceURLModule(url));
  }

  public static Set<String> loadAdditionalFile(
      IClassHierarchy cha, JavaScriptLoader cl, ModuleEntry M) throws IOException {
    try {
      TranslatorToCAst toCAst = getTranslatorFactory().make(new CAstImpl(), M);
      final Set<String> names = new HashSet<>();
      AstTranslator toIR =
          new JSAstTranslator(cl) {
            @Override
            protected void defineFunction(
                CAstEntity N,
                WalkContext definingContext,
                AbstractCFG<SSAInstruction, ? extends IBasicBlock<SSAInstruction>> cfg,
                SymbolTable symtab,
                boolean hasCatchBlock,
                Map<IBasicBlock<SSAInstruction>, TypeReference[]> caughtTypes,
                boolean hasMonitorOp,
                AstLexicalInformation LI,
                DebuggingInformation debugInfo) {
              String fnName = 'L' + composeEntityName(definingContext, N);
              names.add(fnName);
              super.defineFunction(
                  N,
                  definingContext,
                  cfg,
                  symtab,
                  hasCatchBlock,
                  caughtTypes,
                  hasMonitorOp,
                  LI,
                  debugInfo);
            }

            @Override
            protected void leaveFunctionStmt(
                CAstNode n, WalkContext c, CAstVisitor<WalkContext> visitor) {
              CAstEntity fn = (CAstEntity) n.getChild(0).getValue();
              Scope cs = c.currentScope();
              if (!cs.contains(fn.getName())
                  || cs.lookup(fn.getName()).getDefiningScope().getEntity().getKind()
                      == CAstEntity.SCRIPT_ENTITY) {
                int result = processFunctionExpr(n, c);
                assignValue(n, c, cs.lookup(fn.getName()), fn.getName(), result);
              } else {
                super.leaveFunctionStmt(n, c, visitor);
              }
            }
          };
      CAstEntity tree;
      try {
        tree = toCAst.translateToCAst();
        if (DEBUG) {
          CAstPrinter.printTo(tree, new PrintWriter(System.err));
        }
        toIR.translate(tree, M);
        for (String name : names) {
          IClass fcls = cl.lookupClass(name, cha);
          cha.addClass(fcls);
        }
        return names;
      } catch (Error e) {
        return Collections.emptySet();
      }
    } catch (RuntimeException e) {
      return Collections.emptySet();
    }
  }

  public static String simulateToStringForPropertyNames(Object v) {
    // TODO this is very incomplete  --MS
    if (v instanceof String) {
      return (String) v;
    } else if (v instanceof Double) {
      String result = v.toString();
      if ((Math.round((Double) v)) == (Double) v) {
        result = Long.toString(Math.round((Double) v));
      }
      return result;
    } else if (v instanceof Boolean) {
      if ((Boolean) v) {
        return "true";
      } else {
        return "false";
      }
    } else {
      return null;
    }
  }

  public static class Bootstrap implements SourceModule {
    private final String name;
    private final InputStream stream;
    private final URL url;

    public Bootstrap(String name, InputStream stream, URL url) {
      this.name = name;
      this.stream = stream;
      this.url = url;
    }

    @Override
    public Iterator<? extends ModuleEntry> getEntries() {
      return new NonNullSingletonIterator<>(this);
    }

    @Override
    public boolean isClassFile() {
      return false;
    }

    @Override
    public boolean isSourceFile() {
      return true;
    }

    @Override
    public InputStream getInputStream() {
      return stream;
    }

    @Override
    public boolean isModuleFile() {
      return false;
    }

    @Override
    public Module asModule() {
      return this;
    }

    @Override
    public String getClassName() {
      return getName();
    }

    @Override
    public Module getContainer() {
      return null;
    }

    @Override
    public String getName() {
      return name;
    }

    @Override
    public Reader getInputReader() {
      // TODO Auto-generated method stub
      return null;
    }

    @Override
    public URL getURL() {
      return url;
    }
  }

  @SuppressWarnings("resource")
  public static Module getPrologueFile(final String name) {
    return new Bootstrap(
        name,
        JSCallGraphUtil.class.getClassLoader().getResourceAsStream(name),
        JSCallGraphUtil.class.getClassLoader().getResource(name));
  }
}
